•Erosion begins with a process called weathering. In this process, various environmental factors break rock and soil into smaller pieces and loosen them from the earth's surface. One of the chief causes of weathering is the formation of ice. As water freezes, it expands with great force. As a result, when it freezes inside the crack of a rock, it can break the rock apart. Other major agents of weathering include chemicals; living organisms; the movement of air, ice, and heat from the sun.
After materials have been loosened by weathering, they are moved to new locations. For example, winds lift particles from the earth's surface and can carry them over great distances. Glaciers transport materials embedded in them. Raindrops that splash against sloping land move soil particles downhill. Water currents carry materials down a riverbed or out to the sea.
There are 2 types of erosion, namely vertical and lateral erosion, and there are 4 ways in which rivers can erode their channels.